The non-linear Glasma

We study the evolution of quantum fluctuations in the Glasma created immediately after the collision of heavy nuclei. It is shown how the presence of instabilities leads to an enhancement of non-linear interactions among initially small fluctuations. The non-linear dynamics leads to an enhanced growth of fluctuations in a large momentum region exceeding by far the originally unstable band. We investigate the dependence on the coupling constant at weak coupling using classical statistical lattice simulations for SU(2) gauge theory and show how these non-linearities can be analytically understood within the framework of two-particle irreducible (2PI) effective action techniques. The dependence on the coupling constant is only logarithmic in accordance with analytic expectations. Concerning the isotropization of bulk quantities, our results indicate that the system exhibits an order-one anisotropy on parametrically large time scales. Despite this fact, we find that gauge invariant pressure correlation functions seem to exhibit a power law behavior characteristic for wave turbulence.Comment: 16 pages, 7 figures, to appear in Phys. Rev.

Dynamic critical phenomena from spectral functions on the lattice

We investigate spectral functions in the vicinity of the critical temperature of a second-order phase transition. Since critical phenomena in quantum field theories are governed by classical dynamics, universal properties can be computed using real-time lattice simulations. For the example of a relativistic single-component scalar field theory in 2+1 dimensions, we compute the spectral function described by universal scaling functions and extract the dynamic critical exponent z. Together with exactly known static properties of this theory, we obtain a verification from first principles that the relativistic theory is well described by the dynamic universality class of relaxational models with conserved density (Model C).Comment: 18 pages, 6 figures, NPB version, minor change

Turbulence in nonabelian gauge theory

Kolmogorov wave turbulence plays an important role for the thermalization process following plasma instabilities in nonabelian gauge theories. We show that classical-statistical simulations in SU(2) gauge theory indicate a Kolmogorov scaling exponent known from scalar models. In the range of validity of resummed perturbation theory this result is shown to agree with analytical estimates. We study the effect of classical-statistical versus quantum corrections and demonstrate that the latter lead to the absence of turbulence in the far ultraviolet.Comment: 13 pages, 4 figures. PLB version, improved statistics indicates Kolmogorov exponent 4/

A Demand System Analysis of Food for Poor and Non Poor Households. The Case of Argentina

The purpose of this paper is to provide some microeconomics tools to discuss and evaluate public policies that imply transfers of income from the public sector to the poor and their impact on their food demand and calories and nutrient intakes. This study is concerned with the differences in subsistence expenditures, own-price elasticities and income elasticities for two households groups segmented by income: those people below the poverty guideline and those above it. The attention of our research is focused on a demand system for all food groups included in a National Consumption Survey and examines the household food consumption behavior by partitioning the sample. A complete system of demand equations, the Linear Expenditure System (LES), has been used due to its relative empirical expediency. Some additional econometric techniques to correct the bias in the parameter estimates were also applied because of the large number of zero observations in the data. Preliminary estimations following the procedure suggested in the Park et al. (1996) paper, gave some results that they were not as good as we expected and we finally use an alternative one based on Shonkwiler and Yen (1999).Food Demand System, Censored Sample, Own-Price and Income Elasticities, Poverty Status, Demand and Price Analysis,

Basin of attraction for turbulent thermalization and the range of validity of classical-statistical simulations

Different thermalization scenarios for systems with large fields have been proposed in the literature based on classical-statistical lattice simulations approximating the underlying quantum dynamics. We investigate the range of validity of these simulations for condensate driven as well as fluctuation dominated initial conditions for the example of a single component scalar field theory. We show that they lead to the same phenomenon of turbulent thermalization for the whole range of (weak) couplings where the classical-statistical approach is valid. In the turbulent regime we establish the existence of a dual cascade characterized by universal scaling exponents and scaling functions. This complements previous investigations where only the direct energy cascade has been studied for the single component theory. A proposed alternative thermalization scenario for stronger couplings is shown to be beyond the range of validity of classical-statistical simulations.Comment: 11 pages, 10 figures; version published in JHEP (minor revisions

Sophie de Grouchy on the cost of domination in the Letters on Sympathy and two anonymous articles in Le Republicain

Cataloged from PDF version of article.Political writings of eighteenth-century France have been so far mostly overlooked as a source of republican thought. Philosophers such as Condorcet actively promoted the ideal of republicanism in ways that can shed light on current debates. In this paper, I look at one particular source: Le Re´publicain, published in the summer 1791, focusing on previously unattributed articles by Condorcet’s wife and collaborator, Sophie de Grouchy. Grouchy, a philosopher in her own right, is beginning to be known for her Letters on Sympathy, a response to Adam Smith’s Theory of Moral Sentiment, which she published at the same time as her translation of that text into French. I argue, further, that in the texts, which I attribute to Grouchy, we can find the early development of a commercial republican theory, a belief, which is reflected in her discussion of the ‘cost’ of tyranny

Quality Warranties and Food Products in Argentina. What Do Consumers Believe In?

Consumers increasingly demand multiple-quality attributes in food products and value reliable means to identify them. For producers, the effective communication of their products quality is a marketing strategy. Therefore, another market of information associated with the new food markets emerges. This market is closely linked to the institutional environment and the level of trust in different information sources. In this article the emphasis will be put on how the different quality signals provided by the firms in their products affect the consumers´ behaviour. The objective is to investigate domestic consumers' perceptions and beliefs about food quality information in Argentina to identify the mechanisms that fully guarantee this quality. The results indicate that domestic consumers´ perceptions about high quality products are more related to brand names than seals and certifications in labels. This has consequences upon the competitiveness of domestic food market. Quality certification and seller´s reputation are quality warranties restringed only to certain domestic market niches. The households´situation and occupational status seem to be more complex variables that resume the interaction between attitudes, information-processing and actions.food quality, quality warranties, consumers, Argentina, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety, D12, L15,